docs(auth): replace stale 'hermes login' references with 'hermes auth add'

'hermes login' was removed (the command now just prints a deprecation
message and exits). The bundled hermes-agent SKILL.md, in-code error
messages, the tip rotation, the proxy adapters, and the docs site
still pointed agents and users at the dead command — so models loading
the skill kept running 'hermes login --provider openai-codex' and
getting a dead-end print.

Replacements use the canonical 'hermes auth add <provider>' surface
(or bare 'hermes auth' for the interactive manager).

Files:
- skills/autonomous-ai-agents/hermes-agent/SKILL.md (+ regenerated docs page)
- hermes_cli/tips.py (tip rotation)
- agent/google_oauth.py (gemini-cli error message)
- agent/conversation_loop.py (nous re-auth troubleshooting line)
- agent/credential_sources.py (docstring)
- hermes_cli/proxy/cli.py + hermes_cli/proxy/adapters/nous_portal.py (proxy auth hints)
- tests/hermes_cli/test_proxy.py (updated assertions)
- website/docs/reference/faq.md, website/docs/user-guide/features/subscription-proxy.md
- zh-Hans i18n mirrors for the above

'hermes logout' is still a live command and is left untouched.
The 'hermes login' stub in hermes_cli/auth.py:login_command() and
the cli-commands.md 'Deprecated' rows are intentionally kept as
the discoverable deprecation surface.

agent/conversation_loop.py

@@ -2218,7 +2218,7 @@ def run_conversation(
                         print(f"{agent.log_prefix}   Response: {_body_text}")
                     print(f"{agent.log_prefix}   Most likely: Portal OAuth expired, account out of credits, or agent key revoked.")
                     print(f"{agent.log_prefix}   Troubleshooting:")
-                    print(f"{agent.log_prefix}     • Re-authenticate: hermes login --provider nous")
+                    print(f"{agent.log_prefix}     • Re-authenticate: hermes auth add nous")
                     print(f"{agent.log_prefix}     • Check credits / billing: https://portal.nousresearch.com")
                     print(f"{agent.log_prefix}     • Verify stored credentials: {_dhh}/auth.json")
                     print(f"{agent.log_prefix}     • Switch providers temporarily: /model <model> --provider openrouter")

agent/credential_sources.py

@@ -240,11 +240,11 @@ def _clear_auth_store_provider(provider: str) -> bool:
 def _remove_nous_device_code(provider: str, removed) -> RemovalResult:
     """Nous OAuth lives in auth.json providers.nous — clear it and suppress.
 
-    We suppress in addition to clearing because nothing else stops the
-    user's next `hermes login` run from writing providers.nous again
-    before they decide to.  Suppression forces them to go through
-    `hermes auth add nous` to re-engage, which is the documented re-add
-    path and clears the suppression atomically.
+    We suppress in addition to clearing because nothing else stops a future
+    `hermes auth add nous` (or any other path that writes providers.nous)
+    from re-seeding before the user has decided to.  Suppression forces
+    them to go through `hermes auth add nous` to re-engage, which is the
+    documented re-add path and clears the suppression atomically.
     """
     result = RemovalResult()
     if _clear_auth_store_provider(provider):

agent/google_oauth.py

@@ -656,7 +656,7 @@ def get_valid_access_token(*, force_refresh: bool = False) -> str:
     creds = load_credentials()
     if creds is None:
         raise GoogleOAuthError(
-            "No Google OAuth credentials found. Run `hermes login --provider google-gemini-cli` first.",
+            "No Google OAuth credentials found. Run `hermes auth add google-gemini-cli` first.",
             code="google_oauth_not_logged_in",
         )